Effect of Temperature on the Tribological Behavior of HVOF-Sprayed HEA Coatings
Effect of Temperature on the Tribological Behavior of HVOF-Sprayed HEA Coatings
Tuesday, September 29, 2026
High-entropy alloys (HEAs) have attracted significant attention for high-temperature coating applications due to their excellent mechanical properties, thermal stability, and oxidation resistance. In particular, HEA-based coatings are considered promising candidates for improving the wear performance of high-temperature protective systems compared with medium-entropy MCrAlX alloys. In this study, the high-temperature tribological behavior of three thermally sprayed coatings was investigated: FeCoNiCrAl HEA, FeCoNiCrAlYHf HEA containing reactive elements, and a commercial NiCoCrAlYHfTa medium-entropy alloy (Amdry 386-2.5, Oerlikon Metco). All coatings were deposited using the high-velocity oxy-fuel (HVOF) thermal spray process to produce dense coatings. Tribological performance was evaluated under dry sliding conditions using a ball-on-disk configuration at four temperatures: room temperature (RT), 350 °C, 600 °C, and 800 °C. The evolution of friction behavior and wear resistance with increasing temperature was analyzed to assess the influence of alloy composition and reactive element additions. Post-wear surface characterization was performed to identify dominant wear mechanisms and temperature-dependent tribo-oxidation phenomena.
